Welcome to the Ranch
Also, you might have instantiated bagspace once, but you re‑assign it every time you create a new BackPack instance. What you are doing in the constructor is creating a new List containing the elements of the previous List, which looks a good thing to do. It is similar to No 3 in my list in
this post, which tells you definitively I know of four ways to return a List. Since the introduction of the
of() method in List in Java9, there is a fifth way to return a List.
But, as you have already been told, you don't want any of those fields being static. Also, what do size weight and broken refer to? Do they refer to the individual items or the whole backpack?
My favoured option for writing a class is to give it one constructor taking enough parameters to instantiate every field, and initialise every field in that constructor.